1. Field of the Invention
This invention relates to a method and apparatus for retrieving information about an object of interest to an observer. More particularly, it relates to such a method and apparatus for retrieving and displaying information about objects of interest to an observer touring an indoor or outdoor area.
2. Description of the Related Art
Often a person touring a museum, city or the like will want to accompany his tour with the presentation of pertinent information about the exhibits or points of interest he is viewing without having to leaf through a guide book or engage the services of a tour guide. To meet this need, several electronic systems have been developed. Perhaps the oldest and best known is an audio tape player that the person carries which plays descriptions of exhibits in a fixed order and at a fixed pace. The user has to follow the directions on the tape to get to a specific exhibit, then the explanation is played. Thus the user must conform his itinerary to the program, rather than the other way around, and must pause or fast-forward as needed to match his speed with that of the audio presentation.
More recently, electronic systems have been developed that automatically sense an object of interest that a person or vehicle is approaching and play an appropriate description from a repository of such descriptions. Such systems are described, for example, in published PCT applications WO 01/09812 A1, WO 01/35600 A2, and WO 01/42739 A1; U.S. Pat. Nos. 5,614,898, 5,767,795 and 5,896,215; and German patent publication DE19747745A1. All of these system, however, have various disadvantages.
U.S. Pat. No. 5,767,795 describes a vehicle-based system that uses a Global Positioning System (GPS) sensor to retrieve information on adjacent objects from a local repository. In this system, however, the only direction information available (which is derived by examining the position information for successive instants of time) is the direction of the vehicle itself, which is of no help in identifying an object off the path of the vehicle. Also, the data repository is local and must be replicated for each vehicle. U.S. Pat. No. 5,614,898 describes yet another vehicle-based system with similar limitations.
Other systems have been designed for individuals. The systems described in U.S. Pat. No. 5,896,215 and PCT application WO 01/42739 A1 rely on infrared transmitters in the objects of interest. Thus, U.S. Pat. No. 5,896,215 discloses a system in which directional infrared transmitters are used to convey information from exhibit booths to a directional infrared receiver that is either carried by the individual or worn on a badge or on the individual's head. Such systems, however, require the objects to play an active part in the system operation.
PCT application WO 01/35600 A2 describes a personal tour guide system that uses the detected location of a portable unit to access relevant information about an adjacent object of interest. This system does not require the objects to play an active part in the system operation. However, since it uses only position information, it cannot readily discriminate between adjacent objects that may be of interest to the observer. German patent publication DE19747745A1 is similar in this respect.
Another system, described in PCT application WO 01/09812 A1, uses a mobile position sensor together with a direction sensor mounted in a sighting device that the user points at the object of interest. The position and direction information are used to retrieve data on the object being sighted from a local data repository. While this system does not require the objects to play an active part and uses direction information, it requires that the user point the sighting device at the object. Also, since the data is stored locally, the repository has a relatively limited capacity and must be replicated for each user.